Insulator pin



Julyv 6 1926, 1,591,883

c. L. PEIRCE, JR

INSULATOR PIN Filejd May 1922 Fl B .1

1N VEN 7w? WI 77/555458 Patented July 6, 1926.

UNITED STATES CHARLES L. PEIRCE, JR., OF PITTSBURGH, PENNSYLVANIA.

msuna'ron rm.

Application filed May 27,

The invention relates to insulator pins and it has particular relation to insulator pins provided with a screw-threaded thimble or helix upon which the insulator is adapted to be mounted.

One of the objects of the invention is to provide an insulator pin, of the character described, by subjecting stock material, having a substantially circular cross-sectional area, to drop forging processes to form the same into an integral pin, a portion of which is of angular cross section, thereby economizing in material, reducing the manufacturing cost and providing an improved article of less weight than those now on the market.

Another object of the invention is toprovide an insulator pm of the character described, in which the insulator supporting portion is so formed that an insulator engaging thimble or a helical member, such as that illustrated, may be quickly and easily mounted thereon and positively secured in position.

A further object of the invention is to provide an insulator pin adapted to have a wire helix or a supporting thimble mounted thereon and so constructed that the helix may yield to a certain extent to allow for the difference between the coefficient of expansion of the insulator and that of the pin.

With such objects in view, as well as other advantages which may be incident to the utilization of the improvements, the invention consists in the parts and combinations thereof hereinafter set forth and claimed, with the understanding that the several necessary elements constituting the same may be varied in proportion and arrangement without departmg from the nature and scope of the invention.

In order to make the invention more clearly understood, means are shown in the accompanying drawings for carrying the same into practical effect, without limiting the improvements, in their useful applications, to the particular constructions, which, for the purpose of explanation, are made the subject of illustration.

In the accompanying drawin s:

' Figure 1 is a side elevationa view of an insulator pin constructed in accordance with the invention.

Figure 2 is a similar view of the illustrated embodiment of this invention taken from the side as shown inFig. 1 and illustrating the 1922. Serial No. 564,274.

application thereof to a slightly different form of pin.

Figure 3 is a top lan View of the structure illustrated in Fig. 2 and showing the web portion thereof in engagement with a wire helix.

Figure 4 is a horizontal sectional view taken on the line TVIV of Fig. 2 and illustrating the cruciform construction of the pin. t 4" Figure 5 is a horizontal sectional view of another form of insulator pin having three rib portions disposed approximately 120 apart.

Referring to the drawings, a section of rod or bar, of stock material of suitable length and having a substantially circular cross-sectional area, is subjected to a drop forging or a swaging process whereby the same is caused to assume the angular configuration illustrated in the drawings. An integral pin is thus quickly formed having a lower portion 1 which is adapted to engage a cross arm or other suitable supporting member. A collar 2 may be formed integrally with the portion 1 b the same process, if so desired, and is a apted to engage the supporting member to limit the distance into which the screw-threaded portion may enter the same.

The upper, or insulator supporting, portion 3 of the pin is pressed into angular cross-section and is illustrated as comprising a plurality of radially extending'ribs or flanges 4 disposed at right angles to each other and which gradually diminish in crosssectional area toward the upper end of the pin. From an inspection of Figs. 3 and 4 of the drawings, it will be noted, that the insulator supporting portion of the pin thus formed is substantially cruciform in cross sectional area, thereby reatly reducing the weight of the pin wit out materially decreasing the strength thereof.

The upper extremity of the pin is provided with web portions 5 which are formed integrally with the pin and which overhang the alternate spaces .or grooves between the flanges 4. The upper portion of one of the flanges 4 is cut away at a point adjacent to one of the web ortions 5 as is indicated at 6.

A suitable insulator en aging member, shown as consisting of a helicallyformed member 7, is slipped onto the tapered portion 3 of the pin and constitutes the screw threads for engaging the internal screw threads of an insulator, not shown. The extremity of the upper convolution of the member 7 is bent inwardly in a substantially radial direction, as indicated at 8.

After themembcr 7 has been slipped onto the pin it is rotated thereon substantially one quarter of a revolution or a distance sufficient to carry the inwardly bent portion 8 of the upper convolution beneath one of the overhanging web portions 5, in which posi tion it will be disposed flat against one of the flanges 4. The extremity of the lower eonvolutions of the member 7 is then bent inwardly, as indicated at 9, until it engages the side of another one of the flanges t, and is thereby prevented from backward movement such as would disengage the upper bent portion 8 "from the web 5.

While a pin has been shown and described as having a substantially cruciform cross;- sectional area, it will be understood that it may be found to be desirable to form the pin with only three rib portions disposed substantially 120 apart, as illustrated in Fig. 5 to provide a three-point support for the insulator supporting member By such a construction even contact between the pin and the helical member will be insured.

While the insulator supporting member has been shown as comprising a helically formed member, it will be understood that it may be desirable to employ a screwthreaded sleeve or thimble of yieldable material for this purpose. In such case, the upper portion of the pin may be slightly upset over the edge of the sleeve to prevent the displacement thereof.

What I claim is I 1. An insulator pin having a portion adapted to engage a supporting member, a vertically fluted insulator supporting por tion, a helically formed member adapted to yieldably engage said fluted portion to provide screw threads for engagement with an insulator and a web portion carried by said fluted portion adapted to prevent the displacement of said helically formed member.

2. An insulator pin 'having a portion adapted to engage a supporting member, a vertically fluted insulator supporting portion of gradually decreasing cross sectional area, a helical spring adapted to yieldably engage said fluted portion and having an end convolution thereof bent for engagement therewith to prevent the rotation of said spring with respect thereto and a web portion carried by said fluted portion adapted to prevent the displacement of said sprin I 3. An insulator pin' having a portion adapted to engage a supporting member, a vertically ribbed insulator supporting portion provided with a shortened rib, a web formed on said ribbed portion and cooperating with the end of said shortened rib to form a slot and a helical spring engaging said ribbed portion and having a bent end engaging in said slot.

.4. An insulator pin having a threaded stem portion adapted to engage a supporting member, a vertically ribbed insulator supporting portion provided with a shortened rib, a web formed on the end of said ribbed portion and cooperating with the end of said shortened rib to form a slot and a helical spring surrounding said ribbed portion and having a. bent lower end engaging a side of one of said ribs and a bent upper end engaging the opposite side of one of said ribs and received within said slot so as to hold said spring against movement relatively to said pin.

In testimony whereof, I have hereunto subscribed my name this 25th day of May, 1922.

IJ. JR. 

